An OLED device refers to such an electroluminescent device that consists of an organic semiconductor material and a luminous material and is caused to emit light by injection and recombination of carriers that are carried out as the device is driven by an electric field. OLED devices have more advantages, and have bright prospects in the field of display. OLED devices are very sensitive to water vapor and oxygen gas, and water vapor and oxygen gas that permeate into OLED devices are main factors that affect lifetime of the OLED devices. Therefore, OLED devices mostly are encapsulated with an encapsulating structure, so as to serve a function of obstruction to oxygen gas and water vapor.
A laser frit encapsulation is an encapsulating mode for OLED devices, and applied mainly to the encapsulation of OLED devices of a medium size and a small size.
FIG. 1 is a structurally schematic view illustrating an encapsulating structure for a conventional OLED device, in which the laser frit encapsulation is adopted. As shown in FIG. 1, the laser frit encapsulation structure has an upper substrate 03 and a lower substrate 02 disposed in opposition to each other, peripheries of the upper substrate 03 and the lower substrate 02 are sealed and supported by a frit wall 04, an OLED device 01 is positioned within a cavity 05 formed by the upper substrate 03, the lower substrate 02 and the frit wall 04, and the cavity 05 is filled with nitrogen gas.
In the above encapsulation structure for OLED device, the frit wall 04 is formed by heating a frit to melt with the movement of a laser beam. Although the frit wall 04 can have a good obstructing property with respect to water vapor and oxygen gas, adhesion forces between the fit wall 04 and the upper substrate 03 and between the fit wall 04 and the lower substrate 02 may be inadequate, and the frit wall 04 is liable to be broken under the action of an external force. In turn, this causes oxygen gas and water vapor outside the cavity 05 to permeate into the OLED device, and service life of the OLED device is reduced.
Therefore, the encapsulation stability of the conventional OLED encapsulating structure become worse, and then it leads to a lower serve life of the OLED device.